1. Field of the Invention
This invention relates to floor care appliances having a flow of suction air and, more specifically, relates to a floor care appliance wherein suction air pressure may be modified by a variable selective bleed of atmospheric air.
2. Description of the Prior Art
Selective variation of floor care appliance suction pressure, broadly, is old and well known, having appeared in the prior art as early as 1936, for example. Steady improvement and development of this idea has now yielded atmospheric bleed mechanisms which utilize manually actuatable means in a button form so as to improve operator initiated actuation; that is, easy pushbutton operation of a vacuum bleed system has now been provided. Recent examples of this development can be seen in U.S. Pat. No. 3,566,921, issued on Mar. 2, 1971, and U.S. Pat. No. 3,633,239, issued on Jan. 11, 1972.
In each of the exemplary cleaners in these patents, a series of reciprocal buttons are selectively actuated by the user of the floor care appliance so that a desired suction pressure is produced. Further, to make button operation even more efficient, each patent contemplates the use of an automatic cancelling feature for the buttons so that only one button need be depressed for a specific bleed setting which, in turn, cancels the previous button and its particularized suction setting. Thus, less manipulative effort is required by the floor care appliance operator to obtain a desired suction pressure.
A more recent effort in the design of a pushbutton vacuum bleed system is exemplified in U.S. Pat. No. 3,779,283, issued on Dec. 18, 1973. Again, an automatic cancelling feature is provided, with initiation of the buttons of the cleaner in this patent providing a concomittant movement of valve members to obtain the desired vacuum bleed. In this respect, this patent is common with the aforementioned U.S. Pat. No. 3,566,921. These two patents also share the concept of the utilization of non-integrally or permanently connected button-actuated valve members, with the valve members moving, dependent on the initiation of a particular button. Thus, indirect operation of the valve member is provided. However, both these patents do appear to afford an advantage over the other described patent in that operator-initiated movement to actuate the valving arrangement is provided by upstanding buttons which are most easily accessible for actuation by the operator of the floor care appliance.
In contra-distinction to the indirect valve initiation action concept of U.S. Pat. Nos. 3,566,921 and 3,779,283, the aforesaid U.S. Pat. No. 3,633,239 does disclose a valving arrangement in which the valving members and the buttons are integral elements and therefore direct acting but the initiating action required by the operator of the floor care appliance is substantially parallel to the movement of the valve which slides horizontally along the housing of the cleaner. Thus, no generally upstanding, vertically acting, button members are provided which are more easily manipulated by the operator.
Accordingly, it would be advantageous to provide the direct, non-jamming action of a bleed valving arrangement such as shown in U.S. Pat. No. 3,633,239 but, at the same time, provide upstanding vertically actuated buttons which are more easily manipulated by the operator of the cleaner. At the same time, the obviously advantageous automatic cancelling feature in all three of these patents should also be retained so that overall required normal operator button manipulation is minimized, yet individual valve action effectively obtained.
It is, therefore, an object of the invention to provide a vacuum bleed system initiated by upstanding buttons, with the vacuum bleed system also having an automatic cancelling feature.
It is still a further object of the invention to provide a vacuum bleed system in which the buttons directly act to move the valve members to thereby simplify the drive arrangement therebetween.
It is a still further object of the invention to provide for selective vacuum bleed by utilizing a tunnel formed to guide button movement as a portion of the valving system to thereby eliminate the requirement for a series of apertures in the cleaner casing or in a separate valve plate leading to the casing.
It is yet another object of the invention to utilize the single entrance aperture, minimally, but absolutely required as another portion of the valving mechanism for the vacuum bleed system. From this arrangement flows a somewhat simplified vacuum bleed system with a minimum of openings through the housing of the cleaner.